ISS DIY: Home Improvement 220 Miles Above the Earth

Every home requires a little DIY upkeep. Even the $150 billion International Space Station. Sunita Williams, who has taken more space walks and spent more time outside the station than any other female astronaut, tells PM about the challenges of doing maintenance work on the exterior of the International Space Station.

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How does working with tools while wearing a spacesuit compare to reaching for a wrench here on Earth?

It is tricky. It's like being in your garage with a big set of gloves on and trying to handle some of the small tools and not drop them. Here on Earth if you drop stuff, of course, it falls down or on your workbench or maybe in a hard part to get at in your car. But eventually it goes down and you sort of have a general direction of where it goes. If you drop something in space, it's gone. I lost a camera on my very first space walk. Part of the bracket fell apart and that was a sinking feeling, seeing the camera float away and knowing you're never going to get it back. So you have to make sure all your tools are tethered and that they work with the big gloves.

Losing tools just stinks. We don't have Ace Hardware or Sears or Lowe's down the corner, so tools are pretty precious up there.

What is it like working outside the station, where you see the Earth, the stars, and the deep void of space? Do you get a vertiginous, wobbly feeling?

Oh yeah, absolutely. Luckily, on my first space walk I went outside and crawled out the door in the dark and so you don't see all that stuff. Some people might say that sounds scary, but I think that was actually good for me because you stay focused on what you're doing and where you're going. So I drifted over to my work site hand over hand. I got there and started workingit was ammonia lines at the timeand just as the sun came up I felt my hand gripping the handrail a little bit harder. I could see the Earth below zipping by. I was like "Oh my god, where am I?" It finally sort of dawned on me about that I'm really outside and essentially flying formation with the space station at 17,500 miles an hour. You definitely get that feeling and you have to sort of train your brain again.

You spend 40 years living on Earth and knowing what gravity can do to you if you're on top of a building and you fall off. It's hard to erase that in a couple days while you're up in space, but you eventually adapt and then you sort of forget what Earth is like.

On your August 30, 2012, space walk, a routine maintenance task became a nightmare. A bolt to secure the replacement hardware for a failing electrical power distributor called a Main Bus Switching Unit (MBSU) wouldn't drive. You and your fellow spacewalker, Aki Hoshide, discovered metal shavings in the bolt receptacle. After more than eight hours in spacethe third longest space walk in historythe team decided you would strap down the replacement MBSU on the station exterior and return to it on a later space walk. What was that like?

What was going through my mind was, "Oh, you know, it's going to work, we'll figure it out." Something's not quite aligned, we just got to move it around a little bit, like when you're working on your car and you try to thread a bolt and it's not going in exactlyyou just pull it out, put it back in, and try not to do it too hard and not cross thread. You don't want to break anything because one quarter of the power from the solar arrays going to the space station [comes through this MBSU], so it's a pretty huge amount of power.

I think when I saw the hurricane go below us and I realized we were still in the midst of trying to get the MBSU in position that this was going to be a long day. I had looked at the timeline beforehandwe weren't supposed to see that hurricane until we were coming in the door. That was probably about the six hour mark.

The other thought that crossed my mind, which was good, was there's a lot of really smart people on the ground. They have a mockup, they're going to be investigating it. Everyone took a breather, took a step back, and said maybe we don't have enough information at this point in time. Let's just strap [the MBSU] down, come back and think about it.

That's not our normal operating procedure. Usually on a space walk you really want to get stuff done. You want to get out there, get it done, get back inside. It's dangerous work. Nobody likes to put anybody outside just for the heck of it. So I think it was hard for people to give up at that moment in time and say we're not going to do this today.

Personnel at Johnson Space Center in Houston worked around the clock to help get you prepared for an urgent spacewalk on September 5, 2012, to try to reinstall the new MBSU. The Johnson engineers referenced Apollo 13's "failure is not an option" rallying cry as they cobbled together those supplies you had on the station to create makeshift tools. You had to jury-rig a toothbrush, among other things, to address the bolt issue?

Who would've thought we would actually have to tap a housing and make new bolt threads? The typical materials for thatyou know I have them in my garage tooone is something that you want to clean the threads with. That's where the toothbrush came into play. You also want something to run down through the threads, which is a wire brushyou know, typical bore cleaning-type of equipment if you're cleaning any type of tube. Then, a tap and die set, which we scavenged off another piece of equipment that had the same type of bolt and fitting. We flew around the space station on a little scavenger hunt to find all of these things. They then had to be spacewalking compatible, with a tether, so you don't lose these things. And some of the simple things like WD-40we have a different version of that because WD-40 doesn't really work in space. We use Braycote to grease these guys. This is stuff you guys probably talk about all the time in Popular Mechanics, but just a different space version.

You and Aki used the modified wire brush as a cleaning tool and the toothbrush to lubricate the inside of the bolt's housing. After more than four hours of work, you got the new MBSU in place and hooked up. A cheer went up in Houston at mission control. What was your reaction?

When we both got it all wired down there at the very end, I was so happy. I swear to god, tears of joy were running down my face. It was unbelievable, an amazing amount of emotion.

During your last space walk on November 1, 2012, when you fixed a leaking radiator, a mission control person mentioned that you and your fellow space walker should do a "glove check." What's that?

On my first space walk with Bob Curbeam on STS-116 back in 2006, we started seeing these little cuts in the gloves. The space station is getting hit by little micrometeorites all the timeit's just like your car getting hit with little pebbles going down the road. Before every space walk we get a brief that shows pictures of the path where we're going to go to point out where all of these little divots from the micrometeorites are. The divots have these crusty edges that are sharp. Those are the things we attribute some of the glove cuts to.

The gloves have been redesigned. They have a new, thicker RTV [rubberized coating] and what they call Turtleskin that's under the RTV. The gloves nowadays aren't getting these cuts as far as I can tell.

I use my gloves pretty thoroughly; I could feel my hands took a little bit of a beating. Whenever we're doing any real hand-manipulative events, right after that, before we start moving, they want us to just take a look at our gloves. You put your hands in front of your helmet cam so they can see on the ground also. Every time I look at my gloves, we're looking for holes past the RTV and into the Turtleskin, which could then potentially cause a hole in the glove and in the suit.

Fixing things in space sure isn't quite like DIY on planet Earth.

Usually when you're at home in the midst of all that work, you can sit down and have a beer. But up there you can't do that!